As many of you may remember, Percona added the super_read_only feature way back in Percona Server for MySQL 5.6.21, based on work done by WebScaleSQL. This feature eventually found its way into the Community branch of MySQL starting with 5.7.8, and it works the same in both cases. While this is now old news, over the last year I’ve had a couple of inquiries from clients around super_read_only usage in MySQL, and how it works in practice. While the usage of super_read_only is not complex, there is a small caveat that occasionally leads to some confusion around its use. As such, I thought it may be a good idea to write a quick blog post explaining this feature a bit more, and expanding on how it interacts with read_only.

What is super_read_only?

For those unfamiliar, what …

Per Oracle’s Lifetime Support policy, as of Feb 9th, 2021, MySQL Connector/J 5.1 series is covered under Oracle Sustaining Support. Downloadable binaries can be found in the MySQL Products Archives and in the Maven Central Repository.

MySQL Connector/J 5.1.49 has been the last release of Connector/J 5.1 series.

It is time to move on. Users are encouraged to upgrade to MySQL Connector/J 8.0 series which provides the same features as Connector/J 5.1 and a lot more, including a brand new date/time handling support, introduced in version 8.0.23, and the X DevAPI that empowers the MySQL Document Store.

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MySQL Database Service is now easier to use and has flexible deployment options, including High Availability. While creating a new DB System using the web console, users can choose between Standalone, Highly Availability, and HeatWave deployments. The service will pre-populate the necessary fields with the recommended settings. You only need to provide the MySQL user name and password to get MySQL up and running.

With the Standalone option, users get a single-instance MySQL DB System back-ended by the resilient and secure OCI Block Volumes. This option is the most common for test and development environments.

The High Availability option enables applications to meet higher uptime requirements and zero data loss tolerance. When you select the High Availability option, a MySQL DB System with three instances is provisioned across different availability or fault domains. The data is replicated among the instances using a …

MySQL Database Service is now easier to use and has flexible deployment options, including High Availability. While creating a new DB System using the web console, users can choose between Standalone, Highly Availability, and HeatWave deployments. The service will pre-populate the necessary fields w...

Please find below the list of shows where you can find MySQL Community and/or the MySQL team at during April to June 2021:

• April 2021:

  • Data Love Conference/VIRTUAL, April 16, 2021

    • David Stokes, the MySQL Community Manager is going to talk about "Windowing Functions for Database Analytics", for the exact timing please check organizers' website.
  • MidwestPHP/VIRTUAL, April 22-23, 2021
    • David Stokes, the MySQL Community Manager is going to talk about "MySQL 8.0 New Features". The talk is scheduled for 1:50pm-2:30pm on April 22nd. 
    …

Please find below the list of shows where you can find MySQL Community and/or the MySQL team at during April to June 2021:

• April 2021:

  • Data Love Conference/VIRTUAL, April 16, 2021

    • David Stokes, the MySQL Community Manager is going to talk about "Windowing Functions for Database Analytics", for the exact timing please check organizers' website.
  • MidwestPHP/VIRTUAL, April 22-23, 2021
    • David Stokes, the MySQL Community Manager is going to talk about "MySQL 8.0 New Features". The talk is scheduled for 1:50pm-2:30pm on April 22nd. 
    …

Please find below the list of shows where you can find MySQL Community and/or the MySQL team at during April to June 2021: April 2021: Data Love Conference/VIRTUAL, April 16, 2021 David Stokes, the MySQL Community Manager is going to talk about "Windowing Functions for Database Analytics", for the e...

I recently published a blog post over on Medium about the differences in 2 versions of the MySQL COUNT() aggregate function: COUNT(*) and COUNT(column_name or expression). I wanted to share the post here with any readers who may be interested so continue reading for more on this post…

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(based on a conversation with a colleague, and a bit of Twitter

)

A Conundrum

A developer colleague paged me with this:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 2 YEAR) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 2 YEAR) as delta\G
delta: 420

It is obviously wrong, and weirdly so. It only works for “2 year”, not with other values:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-11 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-11 year_month) as delta\G
delta: 3600

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-12 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-12 year_month) as delta\G
delta: 3600

mysql> select …

(based on a conversation with a colleague, and a bit of Twitter)

A Conundrum

A developer colleague paged me with this:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 2 YEAR) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 2 YEAR) as delta\G
delta: 420

It is obviously wrong, and weirdly so. It only works for “2 year”, not with other values:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-11 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-11 year_month) as delta\G
delta: 3600

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-12 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-12 year_month) as delta\G
delta: 3600

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-13 year_month) -
UNIX_TIMESTAMP("2021-03-26 …